Scrape dough down side of bowl (all around) into center, then sprinkle lightly with flour. Cover bowl with a clean kitchen towel (not terry cloth) to keep a crust from forming and let dough rise in a draft-free place at warm room temperature until doubled in bulk, 2 to 2½ hours. (Alternatively,let dough rise in bowl in refrigerator 8 to 12 hours.)

Turn dough out onto a well-floured surface and gently form into a roughly 11- by 8-inch rectangle with floured hands.

Fold dough in thirds (like a letter) with floured hands (dough will be sticky), pressing along seam of each fold to seal.

Put dough, seam side down, in an oiled 9- by 5-inch loaf pan. Cover pan with same clean kitchen towel and let dough rise in a draft-free place at warm room temperature until dough completely fills pan and rises above it slightly, 1 to 1¼ hours.